It's the song "Cat Funeral" From Season 05 Episode 04 of How I Met Your Mother.
Hope I was able to help with these Chords.

Bm   G 
 Cat Funeral

Bm   G
 Cat Funeral

D         F#
It was an accident

D          F#
and not entirely my fault

Bm   G
 Cat Funeral

Bm   G        D       F#
 Cat Funeral

Bm       F#        Bm